Optical recording medium production device and production method

ABSTRACT

A recording medium production device includes a substrate positioning pin vertically movable that performs positioning to a center-hole of a substrate; a substrate holding portion that performs positioning of substrate using the substrate positioning pin to hold the substrate; a cleaner having a gas ejection portion that ejects gas toward the surface of the substrate held by the substrate holding portion, and a gas suction portion that suctions gas; and a substrate positioning pin fixing portion that can press the substrate positioning pin downward. The fixing portion is configured so as not to contact an inner circumferential side surface of the center-hole of substrate. The substrate positioning pin fixing portion descends inside the center-hole of substrate held by the substrate, and presses and fixes the substrate positioning pin. Then the cleaner performs ejection and suction of gas.

TECHNICAL FIELD

The present disclosure relates to an optical recording medium productiondevice and a production method thereof, and particularly to a productiondevice and a production method that removes a foreign material on asubstrate of an optical recording medium.

BACKGROUND ART

As a conventional method for removing a foreign material in aninformation signal layer of an optical recording medium, there is amethod having a process of spraying gas onto at least an exposed surfaceof the information signal layer of a substrate and suctioning the gas inthe vicinity of the exposed surface after a process of forming theinformation signal layer and before a process of forming a lighttransmissive layer (e.g., refer to Patent Literature 1).

PRIOR ART DOCUMENT

Patent Document

-   Patent Literature 1: JP 2001-338443 A

However, in the device that carries out the above-described method forremoving the foreign material, since a neighborhood of an innercircumferential side surface of a center hole of the optical recordingmedium is in contact with a substrate positioning pin, even if the gasis sprayed and suctioned, the foreign material cannot be removedsufficiently.

The present disclosure is to solve the above-described problem. Thepresent disclosure provides an optical recording medium productiondevice and a production method thereof capable of sufficiently removinga foreign material near an inner circumferential side surface of acenter hole of an optical recording medium.

SUMMARY OF THE INVENTION

In order to solve the above-described problem, an optical recordingmedium production device of the present disclosure is an opticalrecording medium production device in which an information signal layeris provided on a substrate, includes:

a substrate positioning pin vertically movable that performs positioningto a center hole of the substrate;

a substrate holding portion that performs the positioning of thesubstrate using the substrate positioning pin to hold the substrate;

a cleaner having a gas ejection portion that ejects gas toward a surfaceof the substrate held by the substrate holding portion, and a gassuction portion that suctions the gas; and

a substrate positioning pin fixing portion that can press the substratepositioning pin downward, and is configured so as not to come intocontact with an inner circumferential side surface of the center hole ofthe substrate;

wherein the substrate positioning pin fixing portion descends inside thecenter hole of the substrate held by the substrate holding portion so asto form a gap in the vicinity of the inner circumferential side surfaceof the center hole of the substrate, and presses and fixes the substratepositioning pin, and in the state, the cleaner performs the ejection andsuction of the gas.

Moreover, in order to solve the above-described problem, an opticalrecording medium production method of the present disclosure includesthe steps of:

holding a substrate positioned by a substrate positioning pin verticallymovable to a center hole of the substrate;

pressing the substrate positioning pin downward and fixing the same soas to expose an inner circumferential side surface of the center hole ofthe substrate; and

removing a foreign material by a cleaner that ejects gas toward asurface of the held substrate and simultaneously suctions the gas.

EFFECT OF THE INVENTION

According to the present disclosure, the optical recording mediumproduction device and the production method thereof can be realized, inwhich the surface of the inner circumferential side surface of thecenter hole of the optical recording medium is exposed during thecleaner operation, by which the foreign material near the innercircumferential side surface of the center hole of the optical recordingmedium can be removed sufficiently.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a view schematically showing an overall process of productionof a disk-shaped optical recording medium.

FIG. 2 is a view showing a schematic configuration of an opticalrecording medium production device to remove a foreign material,according to First Embodiment of the present disclosure.

FIG. 3 is a horizontal cross-sectional view of a forefront portion of acleaner nozzle.

FIG. 4 is a view showing operation to remove the foreign material in theoptical recording medium production device according to First Embodimentof the present disclosure.

FIG. 5 is a view showing a schematic configuration of an opticalrecording medium production device to remove a foreign material,according to Second Embodiment of the present disclosure.

FIG. 6 is a view showing a bottom surface of a cleaner unit opposed to asignal surface of a substrate arranged on a substrate holding portion.

FIG. 7 is a view showing operation to remove the foreign material in theoptical recording medium production device according to SecondEmbodiment of the present disclosure.

FIG. 8 is a view showing a schematic configuration of a productiondevice of an embodiment of the present disclosure, in which anotherconfiguration is employed as a substrate positioning pin fixing portion.

FIG. 9 is view showing a substrate positioning pin and a substratepositioning pin fixing portion that realize one embodiment of thepresent disclosure.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, referring to the drawings, embodiments of the presentdisclosure will be described.

1. First Embodiment

1.1 Production Process of Optical Recording Medium

First, an overall process of production of a disk-shaped opticalrecording medium will be described. FIG. 1 is a view schematicallyshowing an overall process of the production of the disk-shaped opticalrecording medium. The optical recording medium produced by a productionmethod described below is a disk-shaped recording medium in which aninformation signal layer is provided on a substrate, and the substrateis irradiated with light to perform recording and/or reproduction of aninformation signal. As shown in FIG. 1, the overall process of theproduction of the disk-shaped optical recording medium includes asubstrate forming process, a sputtering process, a cover layer process,a back-surface sputtering process, and a printing process, and therespective processes are performed in this order.

First, in the substrate forming process, for example, a disk-shapedpolycarbonate substrate 11 having a thickness 1.1 mm is formed. Next, inthe sputtering process, a target material 12 is sputtered on a signalsurface 13 of the substrate 11 to thereby form a recording film and/or areflection film.

Next, in the cover layer process, in order to protect a surface of thesignal surface 13, a cover layer is formed. Specifically, in this coverlayer process, an ultraviolet curable resin 16 is applied by a resindropping nozzle 15 onto a center cap arranged above a central portion ofthe substrate 11, and further, the applied resin is spread so as to havea uniform thickness on the substrate surface, for example, by a spincoating method, and is then cured by ultraviolet rays. Thereby, thecover layer is formed.

Next, in the back-surface sputtering process, in order to preventwarpage of the substrate due to water absorption, on the opposite sideof the substrate surface with the cover layer formed, a back-surfacesputtering target material 17 is sputtered, by which the waterabsorption preventing film 18 is formed. Finally, in the printingprocess, label printing is performed on the surface with the waterabsorption preventing film 18 formed in the back-surface sputteringprocess.

In the present embodiment, in the overall process of the production ofthe disk-shaped optical recording medium, a foreign material removalsub-process for removing a foreign material such as dust is performedbefore any one of the above-described sputtering process, cover layerprocess, back-surface sputtering process, and printing process.Particularly in the cover layer process, since occurrence of a defectiverecording medium due to foreign material contamination largelydeteriorates a yield ratio in the cover layer process, the foreignmaterial removal of the substrate surface before applying theultraviolet curable resin 16 is very important.

1.1 Configuration of optical recording medium production device

Next, a production device 2 according to First Embodiment of the presentdisclosure will be described. FIG. 2 is a view showing a schematicconfiguration of the optical recording medium production device 2 toremove a foreign material, according to the present embodiment. In thefollowing description, the configuration of the production device 2 whenthe foreign material of the recording medium is removed immediatelybefore the cover layer process is described, and in the productiondevice 2, a substrate 23 after the recording layer and/or the reflectionfilm is formed by sputtering is arranged.

The optical recording medium production device 2 of the presentembodiment includes a rotary shaft 21, a substrate holding portion 22, asubstrate positioning pin 24, a substrate positioning pin fixing portion28, a cleaner nozzle 25, a gas supplying portion 26, and a suction pump27. In FIG. 2, the rotary shaft 21, the substrate holding portion 22,the substrate positioning pin 24, and the substrate positioning pinfixing portion 28 are shown in a vertical cross-sectional view.

The disk-shaped substrate 23, which is a base of the optical recordingmedium, is held by the substrate holding portion 22 moving in tandemwith the rotary shaft 21 rotating at a high speed. The substrate holdingportion 22 holds the substrate 23 by an action such as vacuum suctionand the like.

As shown in FIG. 2, in a vertical direction in central portions of therotary shaft 21 and the substrate holding portion 22, a cylindrical holehaving the same diameter as a diameter of a center hole of the substrate23 is provided. Inside this cylindrical hole, the columnar substratepositioning pin 24 is arranged. While the substrate positioning pin 24is arranged without any gap inside the cylindrical hole of the rotaryshaft 21 and the substrate holding portion 22, it is configured operablyin a direction perpendicular to the signal surface 13 of the substrate23. This substrate positioning pin 24 is provided to position thesubstrate 23 on the substrate holding portion 22. That is, the substratepositioning pin 24 is biased from below by an elastic body (not shown)such as a spring so as to slightly protrude an upper surface thereoffrom the signal surface 13 of the substrate 23 when positioning thesubstrate 23, and so as to lower a vertical position inside thecylindrical hole when pressing the upper surface downward.

The substrate positioning pin fixing portion 28 is provided at aposition corresponding to the substrate positioning pin 24 above thesubstrate positioning pin 24. The substrate positioning pin fixingportion 28 vertically descends to be fixed in the state pressing thesubstrate positioning pin 24. That is, the substrate positioning pin 24and the substrate positioning pin fixing portion 28 are fixed to eachother in contact. By fixing them to each other in this manner, each ofcontact surfaces between the substrate positioning pin 24 and thesubstrate positioning pin fixing portion 28 is not worn even when therotary shaft 21 and the substrate holding portion 22 rotate, and thus,occurrence of a foreign material during rotary motion of the rotaryshaft 21 and the substrate holding portion 22 can be suppressed.Therefore, both the substrate positioning pin 24 and the substratepositioning pin fixing portion 28 are preferably made of magnetic fieldgenerating bodies such as magnets. Alternatively, one of the substratepositioning pin 24 and the substrate positioning pin fixing portion 28may be made of the magnetic field generating body such as a magnet, andthe other may be made of a magnetic body.

As described later, when the substrate positioning pin fixing portion 28presses the substrate positioning pin 24, a gap (space) is preferablyformed inside an inner circumferential side surface 30 of the centerhole of the substrate 23, that is, a surface of the innercircumferential side surface 30 is preferably exposed. That is, at thistime, preferably, the substrate positioning pin fixing portion 28 doesnot come into contact with the inner circumferential side surface 30 ofthe center hole of the substrate 23. For this, a lateral width of thesubstrate positioning pin fixing portion 28 is preferably smaller than adiameter of a circular cross section of the substrate positioning pin24. Specifically, preferably, for example, the substrate positioning pinfixing portion 28 has a columnar shape, and a diameter of a circularcross section thereof is smaller than the diameter of the circular crosssection of the substrate positioning pin 24.

Furthermore, the cleaner nozzle 25 is provided in opposition to thesignal surface 13 of the substrate 23. The cleaner nozzle 25 performsthe ejection of gas and the suction of the gas at a forefront portionthereof in order to remove the foreign material. Accordingly, as shownin FIG. 2, the forefront portion of the cleaner nozzle 25 is arranged inopposition to the signal surface 13 of the substrate 23 and at adistance of several millimeters from the signal surface 13 of thesubstrate 23. Furthermore, in the present embodiment, the forefrontportion of the cleaner nozzle 25 is configured movably on a parallelplane at a distance of several millimeters from the signal surface 13 ofthe substrate 23, from a center hole vicinity of the substrate 23 to anouter circumferential vicinity, or from the outer circumferentialvicinity of the substrate 23 to the center hole vicinity in a radialdirection of the substrate 23. As described later, preferably, when theforefront portion of the cleaner nozzle 25 exists in the center holevicinity of the substrate 23, the forefront portion approaches a portionslightly closer to a center of the center hole than the innercircumferential side surface 30 of the center hole of the substrate 23.

FIG. 3 is a horizontal cross-section of the forefront portion of thecleaner nozzle 25. In the cleaner nozzle 25, a gas ejection nozzle 25 bto perform gas ejection is provided, and a gas suction nozzle 25 a toperform suction of the gas is provided so as to surround the gasejection nozzle. A gas supply portion 26 shown in FIG. 2 supplies thehigh-pressure gas to a surface of the substrate 23 through the gasejection nozzle 25 b of the cleaner nozzle 25. The suction pump 27suctions the gas through the gas suction nozzle 25 a of the cleanernozzle 25.

1.2. Operation of Optical Recording Medium Production Device

Next, operation to remove the foreign material of the production device2 according to the present embodiment will be described. FIG. 4 is aview for describing the operation to remove the foreign material of theoptical recording medium production device 2 according to the presentembodiment.

First, as shown in FIG. 2, the substrate 23 is placed on the substrateholding portion 22 with reference to the substrate positioning pin 24and is held by the substrate holding portion 22 by the action such asvacuum suction. In this state, the substrate positioning pin fixingportion 28 presses the substrate positioning pin 24, and mutualpositions are fixed by actions of the magnets in this state. At thistime, as shown in FIG. 4, the substrate positioning pin fixing portion28 presses the substrate positioning pin 24, by which the gap (space) isformed between the inner circumferential side surface 30 of the centerhole of the substrate 23, and the substrate positioning pin fixingportion 28 and the substrate positioning pin 24. In order to form thegap (space) in this manner, the lateral width of the substratepositioning pin fixing portion 28 is preferably smaller than thediameter of the circular cross section of the substrate positioning pin24.

Next, the substrate holding portion 22 is rotated by the rotary motionof the rotary shaft 21, and this rotary motion allows the substrate 23held by the substrate holding portion 22 to be rotated similarly. Thisrotation of the substrate 23 and the movement in the radial direction ofthe cleaner nozzle 25 described below may remove the foreign materialexisting at every position on the upper surface of the substrate 23.

The forefront portion of the cleaner nozzle 25 is translated in theradial direction of the substrate 23 from the center hole vicinity tothe outer circumferential vicinity of the substrate 23, or from theouter circumferential vicinity to the center hole vicinity of thesubstrate 23 at the distance of several millimeters from the signalsurface 13 of the substrate 23. When the forefront portion of thecleaner nozzle 25 exists in the center hole vicinity of the substrate23, the forefront portion preferably approaches the portion slightlycloser to the center of the center hole than the inner circumferentialside surface 30 of the center hole of the substrate 23.

The forefront portion of the cleaner nozzle 25 simultaneously performsthe ejection of the gas and the suction of the gas toward the surface ofthe substrate 23 to thereby remove the foreign material on the surfaceof the substrate 23. At this time, the substrate positioning pin fixingportion 28 presses the substrate positioning pin 24, by which the gap(space) is formed between the inner circumferential side surface 30 ofthe center hole of the substrate 23, and the substrate positioning pinfixing portion 28 and the substrate positioning pin 24, so that theforefront portion of the cleaner nozzle 25 can suction and remove theforeign material near the inner circumferential side surface 30 of thecenter hole of the substrate 23 sufficiently and efficiently.Furthermore, if the forefront portion of the cleaner nozzle 25 canapproach the portion slightly closer to the center hole center than theinner circumferential side surface 30 of the center hole of thesubstrate 23, the foreign material near the inner circumferential sidesurface 30 of the center hole of the substrate 23 can be removed moresufficiently and more efficiently.

Moreover, in the optical recording medium production device 2 to removethe foreign material according to the present embodiment, since thesubstrate positioning pin 24 is fixed by the substrate positioning pinfixing portion 28, each of the mutual contact surfaces is not worn evenwhen the rotary shaft 21 and the substrate holding portion 22 rotate,and thus, the occurrence of the foreign material during the rotarymotion of the rotary shaft 21 and the substrate holding portion 22 canbe eliminated.

1.3. Conclusion

In the optical recording medium production device 2 according to FirstEmbodiment, the substrate positioning pin fixing portion 28 presses thesubstrate positioning pin 24, by which the gap (space) is formed betweenthe inner circumferential side surface 30 of the center hole of thesubstrate 23, and the substrate positioning pin fixing portion 28 andthe substrate positioning pin 24. Moreover, the forefront portion of thecleaner nozzle 25 can approach the portion slightly closer to the centerhole center than the inner circumferential side surface 30 of the centerhole of the substrate 23. These allows the inner circumferential sidesurface 30 of the center hole of the substrate 23 to be exposed, and theforeign material near the inner circumferential side surface 30 of thecenter hole of the substrate 23 to be removed sufficiently andefficiently. Furthermore, since the substrate positioning pin 24 isfixed by the substrate positioning pin fixing portion 28, the occurrenceof the foreign material, which may be caused by friction of thesubstrate positioning pin 24 and the substrate positioning pin fixingportion 28 during the rotary motion of the rotary shaft 21 and thesubstrate holding portion 22, is suppressed.

2. Second Embodiment

2.1. Configuration of Optical Recording Medium Production Device

A production device according to Second Embodiment of the presentdisclosure will be described. FIG. 5 is a view showing a schematicconfiguration of the optical recording medium production deviceaccording to the present embodiment. In a production device 42 accordingto Second Embodiment, since configurations of a rotary shaft 21, asubstrate holding portion 22, and a substrate positioning pin 24 aresimilar to those of First Embodiment, detailed descriptions are omitted.In the following description, the configuration of the production device42 is also shown when a foreign material of a recording medium isremoved immediately before the cover layer process, and in theproduction device, a substrate 23 in a state after a recording layerand/or a reflection film is formed by sputtering is arranged.

The production device 42 according to Second Embodiment of the presentdisclosure is different from the production device of First Embodimentof the present disclosure in that a substrate positioning pin fixingportion 52 and a cleaner unit 51 that performs ejection of gas andsuction of the gas to remove the foreign material are integrallyconfigured.

FIG. 6 is a view when the cleaner unit 51 is seen from a side opposed toa signal surface 13 of the substrate 23 arranged on the substrateholding portion 22, that is, from an opening portion side of the cleanerunit 51. The cleaner unit 51 according to Second Embodiment has aschematic rectangular parallelepiped shape, and as shown in FIG. 5, alongitudinal dimension thereof is beyond a radius of the substrate 23.

As shown in FIG. 6, at a bottom surface of the cleaner unit 51 accordingto Second Embodiment, in order to remove the foreign material moreefficiently, one gas ejection portion 51 b and two gas suction portions51 a, which each have a slit shape, are arranged in parallel in alongitudinal direction of the cleaner unit 51. The one gas ejectionportion 51 b is arranged at a center of the bottom surface of thecleaner unit 51, and the two gas suction portions 51 b are each arrangednear an edge portion of the bottom surface of the cleaner unit 51.Moreover, the substrate positioning pin fixing portion 52 is providedbetween the gas ejection portion 51 b and any one of the gas suctionportions 51 a. The substrate positioning pin fixing portion 52 may beprovided at another position of the bottom surface of the cleaner unit51, and for example, may be provided at a position in the middle so asto obstruct a part of the slit-shaped gas ejection portion 51 b.Moreover, while in the cleaner unit 51 shown in FIG. 6, the one gasejection portion 51 b and the two gas suction portions 51 a areprovided, a larger number of gas ejection portions 51 b and gas suctionportions 51 a may be provided.

The high-pressure gas ejected onto a surface of the substrate 23 throughthe gas ejection portion 51 b in a bottom surface of the cleaner unit 51is supplied by a gas supply portion 26 connected to the cleaner unit 51.The gas suctioned from the surface of the substrate 23 through the gassuction portions 51 a in the bottom surface of the cleaner unit 51 issuctioned by a suction pump 27 connected to the cleaner unit 51.

The substrate positioning pin fixing portion 52 configured integrallywith the cleaner unit 51 is similar to the substrate positioning pinfixing portion 28 in the production device 2 according to FirstEmbodiment. The substrate positioning pin fixing portion 52 verticallydescends to be mutually fixed in the state pressing the substratepositioning pin 24. By fixing them to each other in this manner, each ofcontact surfaces between the substrate positioning pin 24 and thesubstrate positioning pin fixing portion 52 is not worn even when therotary shaft 21 and the substrate holding portion 22 rotate, and thus,occurrence of the foreign material during rotary motion of the rotaryshaft 21 and the substrate holding portion 22 can be suppressed.Therefore, both the substrate positioning pin 24 and the substratepositioning pin fixing portion 52 are preferably made of magnetic fieldgenerating bodies such as magnets. Alternatively, one of the substratepositioning pin 24 and the substrate positioning pin fixing portion 52may be made of the magnetic field generating body such as a magnet, andthe other may be made of a magnetic body.

Moreover, when the substrate positioning pin fixing portion 52 pressesthe substrate positioning pin 24, a gap (space) is preferably formedinside an inner circumferential side surface 30 of a center hole of thesubstrate 23, that is, a surface of the inner circumferential sidesurface 30 is preferably exposed. That is, at this time, preferably, thesubstrate positioning pin fixing portion 52 does not come into contactwith the inner circumferential side surface 30 of the center hole of thesubstrate 23. For this, a lateral width of the substrate positioning pinfixing portion 52 is preferably smaller than a diameter of a circularcross section of the substrate positioning pin 24. Specifically,preferably, for example, the substrate positioning pin fixing portion 52has a columnar shape, and a diameter of a circular cross section thereofis smaller than the diameter of the circular cross section of thesubstrate positioning pin 24.

Moreover, in the state where the substrate positioning pin fixingportion 52 presses the substrate positioning pin 24 to be fixed, thesubstrate positioning pin fixing portion 52 and the bottom surface ofthe cleaner unit 51 are configured so that the bottom surface of thecleaner unit 51 is arranged at a distance of several millimeters abovethe signal surface 13 of the substrate 23.

2.2. Operation of Optical Recording Medium Production Device

Next, operation to remove the foreign material of the production device42 according to the present embodiment will be described. FIG. 7 is aview for describing the operation to remove the foreign material of theoptical recording medium production device 42 according to the presentembodiment. Since the operations of the rotary shaft 21, the substrateholding portion 22, and the substrate positioning pin 24 are similar tothose in First Embodiment, detailed descriptions are omitted.

First, as shown in FIG. 5, the substrate 23 is placed on the substrateholding portion 22 with reference to the substrate positioning pin 24and is held by the substrate holding portion 22 by the action such asvacuum suction. In this state, the substrate positioning pin fixingportion 52 configured integrally with the cleaner unit 51 presses thesubstrate positioning pin 24, and mutual positions are fixed by actionsof the magnets in this state. At this time, as shown in FIG. 7, thesubstrate positioning pin fixing portion 52 presses the substratepositioning pin 24, by which the gap (space) is formed between the innercircumferential side surface of the center hole of the substrate 23, andthe substrate positioning pin fixing portion 52 and the substratepositioning pin 24. In order to form the gap (space) in this manner, thelateral width of the substrate positioning pin fixing portion 52 ispreferably smaller than the diameter of the circular cross section ofthe substrate positioning pin 24.

When the substrate positioning pin fixing portion 52 presses thesubstrate positioning pin 24, and the mutual positions are fixed by theactions of the magnets, the cleaner unit 51 bottom surface is arrangedat a distance of several millimeters above the signal surface 13 of thesubstrate 23.

Next, the substrate holding portion 22 is rotated by the rotary motionof the rotary shaft 21, and this rotary motion allows the substrate 23held by the substrate holding portion 22 to be also rotated similarly.By this rotation of the substrate 23 and the arrangement of the cleanerunit 51 including, in the bottom suface, the slit-shaped gas ejectionportion 51 b and the similar slit-shaped gas suction portions 51 a,which are longer than the radius of the substrate 23, the foreignmaterial existing at every position of the upper surface of thesubstrate 23 may be removed.

The gas ejection portion 51 b and the gas suction portions 51 a in thebottom surface of the cleaner unit 51 are arranged at a distance ofseveral millimeters above the signal surface 13 of the substrate 23. Asshown in FIG. 6, since the gas ejection portion 51 b and one of the gassuction portions 51 a are arranged so as to sandwich the substratepositioning pin fixing portion 52, a part of the gas ejection portion 51b and a part of the gas suction portion 51 a in the vicinity of thesubstrate positioning pin fixing portion 52 are above the positioncloser to the center of the center hole than the circumferential sidesurface 30 of the center hole of the substrate 23.

The cleaner unit 51 simultaneously performs the ejection and the suctionof the gas to thereby remove the foreign material of the surface of thesubstrate 23. At this time, the substrate positioning pin fixing portion52 continues to press the substrate positioning pin 24, by which the gap(space) is formed between the inner circumferential side surface 30 ofthe center hole of the substrate 23, and the substrate positioning pinfixing portion 52 and the substrate positioning pin 24, so that the gasejection portion 51 b and the gas suction portions 51 a of the cleanerunit 51 can suction and remove the foreign material near the innercircumferential side surface 30 of the center hole of the substrate 23sufficiently and efficiently. Also, since the part of the gas ejectionportion 51 b and the part of the gas suction portion 51 a in thevicinity of the substrate positioning pin fixing portion 52 areimmediately above the portion closer to the center of the center holethan the inner circumferential side surface 30 of the center hole of thesubstrate 23, the foreign material near the circumferential side surface30 of the center hole of the substrate 23 can be removed moresufficiently and efficiently.

A longitudinal dimension of the cleaner unit 51 may be nearly equal tothe diameter of the substrate 23, or may be beyond the diameter of thesubstrate 23. In these cases, the foreign material can be removed morequickly and more surely.

2.3. Conclusion

Since as in First Embodiment, the optical recording medium productiondevice 2 according to Second Embodiment also enables the space to beformed near the inner circumferential side surface 30 of the center holeof the substrate 23 during cleaning operation, the foreign material nearthe inner circumferential side surface 30 of the center hole of thesubstrate 23 may be removed sufficiently and efficiently. Furthermore,since the substrate positioning pin 24 is fixed by the substratepositioning pin fixing portion 52, the occurrence of the foreignmaterial, which may be caused by friction of the substrate positioningpin 24 and the substrate positioning pin fixing portion 52 during therotary motion of the rotary shaft 21 and the substrate holding portion22, is suppressed.

Further, in the production device according to Second Embodiment, sincea movement mechanism of the cleaner nozzle is not required, the overallconfiguration of the production device can be simplified as comparedwith First Embodiment.

3. Other Embodiments

While in the foregoing, First and Second Embodiments of the presentdisclosure have been described, the present disclosure is not limited tothe above-described embodiments.

In both the production device according to First Embodiment and theproduction device according to Second Embodiment, all of the substratepositioning pin 24, the substrate positioning pin fixing portions 28, 52are each made of the magnetic field generating body such as the magnet,or one of the substrate positioning pin 24 and the substrate positioningpin fixing portions 28, 52 is made of the magnetic field generating bodysuch as the magnet, and the other is made of the magnetic body. That is,when coming into contact with each other, both are mutually fixed. Inthis manner, as long as the mutual fixation when both come into contactwith each other is realized, for the substrate positioning pin fixingportion, another configuration may be employed.

FIG. 8 is a view showing a schematic configuration of a productiondevice 62 according to another embodiment of the present disclosure, inwhich another configuration is employed as a substrate positioning pinfixing portion 81. The substrate positioning pin fixing portion 81 shownin FIG. 8 is connected to a vacuum pump 82. The substrate positioningpin fixing portion 81 can press a substrate positioning pin 24, andfurther, in a pressing state, the substrate positioning pin fixingportion 81 can fix the substrate positioning pin 24 while performingvacuum suction by the operation of the vacuum pump 82. With thisconfiguration, each of contact surfaces between the substratepositioning pin fixing portion 81 and the substrate positioning pin 24is not worn even when a rotary shaft 21 and a substrate holding portion22 rotate, and thus, occurrence of a foreign material during rotarymotion of the rotary shaft 21 and the substrate holding portion 22 canbe suppressed.

Although not illustrated, for a cleaner nozzle 25, a gas supply portion26 and a suction pump 27, those according to First Embodiment shown inFIGS. 2 and 4 are preferably used.

Moreover, an embodiment of the present disclosure may be realized, evenif when the substrate positioning pin fixing portion and the substratepositioning pin come into contact with each other, both are notcompletely stuck to each other. FIG. 9 is views showing a substratepositioning pin 24 b and a substrate positioning pin fixing portion 28a, which realize still another embodiment of the present disclosure. Thesubstrate positioning pin fixing portion 28 a has a substantiallycolumnar shape (refer to FIG. 9(1 a)), and includes a projected portion55 having a trident shape at a forefront portion thereof. FIG. 9(2 a)shows a bottom view when the substrate positioning pin fixing portion 28a shown in FIG. 9(1 a) is seen from arrow A.

The substrate positioning pin 24 b also has substantially columnar shape(refer to FIG. 9(1 b)), and includes, in an upper surface thereof, acircumferential edge and three tooth-like projected portions 57 thatreceive and are engaged with the projected portion 55 of the substratepositioning pin fixing portion 28 a. FIG. 9(2 b) shows a top view whenthe substrate positioning pin 24 b shown in FIG. 9(1 b) is seen fromarrow B.

Components other than the substrate positioning pin 24 b and thesubstrate positioning pin fixing portion 28 a only need to be similar tothose in the production device according to First Embodiment, or in theproduction device according to Second Embodiment.

When the forefront portion of the substrate positioning pin fixingportion 28 a and the upper surface of the substrate positioning pin 24 bare joined and the substrate positioning pin 24 b is rotated in adirection of rotation arrow p (or the substrate positioning pin fixingportion 28 a is rotated in a direction of rotation arrow α), mutualpositions of the substrate positioning pin fixing portion 28 a and thesubstrate positioning pin 24 b are engaged and fixed, as shown in FIG.9(3). That is, the projected portion 55 in the forefront portion of thesubstrate positioning pin fixing portion 28 a and the tooth-likeprojected portions 57 in an upper surface of the substrate positioningpin 24 b are engaged, which prevents both from mutually rotating anymore.

In this manner, since the positions in the rotation direction of thesubstrate positioning pin fixing portion 28 a and the substratepositioning pin 24 b are fixed even when a rotary shaft 21 and asubstrate holding portion 22 rotate, each of contact surfacestherebetween is not worn, and thus, occurrence of a foreign materialduring rotary motion of the rotary shaft 21 and the substrate holdingportion 22 can be suppressed.

While in the foregoing, the production device according to each of theembodiments of the present disclosure has been described as the devicethat removes the foreign material of the recording medium immediatelybefore the cover layer process shown in FIG. 1, the production deviceaccording to each of the embodiments of the present disclosure canremove a foreign material of the recording medium in the otherprocesses. For example, while in FIG. 1, the sputtering process, theback-surface sputtering process, the printing process and the likeincluded in the overall process of the production of the opticalrecording medium are shown, the production device according to each ofthe embodiments of the present disclosure can be also used as a devicethat removes the foreign material of the recording medium immediatelybefore each of these processes.

EXPLANATION OF REFERENCES

2, 42, 62 production device

11 polycarbonate substrate

12 target material

13 signal surface

14 center cap

15 resin dropping nozzle

16 ultraviolet curable resin

17 back-surface sputtering target

18 water absorption preventing film

21 rotary shaft

22 substrate holding portion

23 substrate

24, 24 b substrate positioning pin

25 cleaner nozzle

25 a gas suction nozzle

25 b gas ejection nozzle

26 gas supply portion

27 suction pump

28, 28 a, 52, 81 substrate positioning pin fixing portion

30 center hole inner circumferential side surface

51 cleaner unit

51 a gas suction portion

51 b gas ejection portion

55 projected portion

57 tooth-like projected portion

82 vacuum pump

The invention claimed is:
 1. An optical recording medium productiondevice in which an information signal layer is provided on a substrate,comprising: a substrate positioning pin vertically movable that performspositioning to a center hole of the substrate; a substrate holdingportion that performs the positioning of the substrate using thesubstrate positioning pin to hold the substrate; a cleaner having a gasejection portion that ejects gas toward a surface of the substrate heldby the substrate holding portion, and a gas suction portion thatsuctions the gas; and a substrate positioning pin fixing portion thatcan press the substrate positioning pin downward, and is configured soas not to come into contact with an inner circumferential side surfaceof the center hole of the substrate; wherein the substrate positioningpin fixing portion descends inside the center hole of the substrate heldby the substrate holding portion so as to form a gap in the vicinity ofthe inner circumferential side surface of the center hole of thesubstrate, and presses and fixes the substrate positioning pin, and inthe state, the cleaner performs the ejection and suction of the gas. 2.The production device according to claim 1, wherein the substratepositioning pin fixing portion has a columnar shape, and a diameter of acircular cross section thereof is smaller than a diameter of a circularcross section of the substrate positioning pin.
 3. The production deviceaccording to claim 1, wherein in the state where the substratepositioning pin fixing portion descends inside the center hole of thesubstrate held by the substrate holding portion so as to form the gap inthe vicinity of the inner circumferential side surface of the centerhole of the substrate, and presses and fixes the substrate positioningpin, a part of the gas ejection portion and a part of the gas suctionportion of the cleaner can move up to an inner position from the innercircumferential side surface of the substrate held by the substrateholding portion.
 4. The production device according to claim 1, whereinthe cleaner and the substrate positioning pin fixing portion areintegrally configured.
 5. The production device according to claim 1,wherein one of the substrate positioning pin and the substratepositioning pin fixing portion is made of a magnetic field generatingbody, and the other is made of a magnetic body.
 6. The production deviceaccording to claim 1, wherein both the substrate positioning pin and thesubstrate positioning pin fixing portion are each made of a magneticfield generating body.
 7. The production device according to claim 1,wherein the substrate positioning pin fixing portion fixes the substratepositioning pin by vacuum suction in a state where the substratepositioning pin is pressed.
 8. The production device according to claim1, wherein the cleaner performs the ejection and the suction of the gasto a surface side on which the information signal layer is provided. 9.The production device according to claim 1, wherein the cleaner performsthe ejection and the suction of the gas to a printing surface side ofthe optical recording medium.